This invention relates to a pattern forming method of manufacturing a semiconductor or the like that has a fine pattern.
A forming process using a beam of electrons or charged particles is capable of forming a pattern with a line thickness below 0.25 .mu. which can be hardly obtained by photolithography, and hence, it is considered that the prospects for developing a dynamic memory of 256 megabits to 1 gigabit is excellent. A batch transfer process which can assure a high throughput is efficient to mass-produce the semiconductor memory. For example, in a batch transfer process of semiconductor memory chip pattern disclosed in MONTHLY SEMICONDUCTOR WORLD 1990, 7, P170 "Electron beam block exposure technique", the whole pattern of a chip 61 is formed with the repetition of exposure to a block 23 by making use of the regularity of a memory cell circuit pattern in such a manner that a substrate (wafer) 22 is exposed repeatedly with use of a mask 51 containing a regular region which serves as a block 52 as shown in FIG. 4 while it being moved by a distance corresponding to exposure shots as indicated by arrow marks l.sub.1 and l.sub.2.
However, in the conventional method shown in FIG. 4, even with the repetitions of exposure by making use of the mask 51 of the same form, backscattered electrons from the surroundings contribute less to the exposure to a resist on the peripheral portion of the chip 61 than that on the central portion thereof, resulting in what is called "proximity effect" brought about by the insufficient exposure. This gives rise to a problem that, after exposure and developing, the line thickness of the pattern 25 in the peripheral portion of the chip becomes thinner as compared with that of the pattern 24 in the central portion of the chip as shown in FIG. 5, for example. For this reason, according to the exposure process using the conventional mask, it is impossible to make correction for the proximity effect caused due to the backscattering of electrons during the exposure process.